Patent FR2 630 476 in the name of Fernand SCHERRER especially discloses false stretched ceilings which comprise both a frame fixed to the walls or to the ceiling of a room, this frame being formed by an external stringer in turn comprising butted profiles, and also a stretched flexible sheet inside this frame, this flexible sheet comprising a sheet of plastic material or a fabric. The flexible sheet is kept stretched due to hooking, on the stringer, of a border solid with the sheet forming a harpoon, this border having a cross-section in the form of a hook clinging to a shoulder extending over the entire periphery of the external flange of the stringer.
These known false walls rest on the principle of tensing the flexible sheet on the frame, perfectly flat, horizontally or vertically according to whether it is a false ceiling or a false wall.
Once mounted on their stringer these false ceilings or false walls necessarily frequently show considerable and therefore visible clearance between the periphery of the stretched wall and the walls supporting the hooking stringers. This functional clearance necessarily results from the need to provide sufficient gap between the wall and the stretched surface to insert the peripheral hooks of the sheet inside the stringers such that the end bead of the harpoon fits into a shoulder provided for this purpose on the external flange of the stringer nearest the wall, as shown in FIG. 1, for example.
This residual gap enabling assembly and especially disassembly by insertion of a spatula inside the hook of the sheet is now of the order of 4 to 5 mm minimum.
In numerous cases, this residual gap between the sheet and the wall can be visually offputting as it comprises a hollow joint sometimes giving a highly unaesthetic impression; this the case especially when fabrics are stretched in rooms where the wall and the ceiling must not include any hollow joint to get better presentation; similarly, in numerous installations it is important that the hollow joint between the fabric and the walls be as small as possible to avoid unintended passages of air causing smearing or which are likely to unbalance some aeration installations.